Three-Dimensional Computer Modelling

1. A method of processing image data defining images of a subject object to generate data defining a three-dimensional computer model of the subject object, comprising: calculating the imaging positions and orientations of at least some of the images to generate a plurality of respective registered sets of images, at least one of the sets containing a plurality of images and each other set containing at least one image, and the images within each respective set which contains more than one image having imaging positions and orientations registered to each other; generating a preliminary three-dimensional computer model of the subject object using at least some of the images from a first registered set containing a plurality of images; registering all of the respective registered sets of images by registering the preliminary three-dimensional computer model with each registered set of images other than the first set, the registration with each set being carried out by projecting the preliminary three-dimensional computer model into at least one image in the set; and generating a refined three-dimensional computer model of the subject object using the calculated registration of the different sets.

2. A method according to claim 1 , wherein the imaging positions and orientations of the images in at least one set are calculated relative to a predetermined calibration pattern.

3. A method according to claim 1 , wherein the imaging positions and orientations of the images in at least one set are calculated relative to each other in dependence upon the positions of matching features in different images.

4. A method according to claim 1 , wherein the imaging positions and orientations of the images in at least one set are calculated in dependence upon features in the images identified by a user.

5. A method according to claim 1 , wherein the imaging positions and onentations of the images in at least one set are calculated by processing the image data to detect features in different images, and calculating the relative imaging positions and orientations in dependence upon the detected features.

6. A method according to claim 1 , wherein the registration of the preliminary three-dimensional computer model with each registered set of images comprises iteratively projecting the preliminary three-dimensional computer model into at least one image in the set and changing the relative position and orientation of the preliminary three-dimensional computer model and the registered set of images.

7. A method according to claim 1 , wherein the registration of the preliminary three-dimensional computer model with at least one registered set of images comprises: projecting the preliminary three-dimensional computer model into at least one image in the set; generating image data for display showing the projection of the preliminary three-dimensional computer model relative to the imaged subject object in each image into which the preliminary three-dimensional computer model is projected; changing the relative position and orientation of the preliminary three-dimensional computer model and the registered set of images in accordance with signals input by a user; and updating the image data for display as the relative position and orientation of the preliminary three-dimensional computer model and the registered set of images is changed.

8. A method according to claim 7 , wherein the image data generated for display comprises image data showing the silhouette of the projected preliminary three-dimensional computer model relative to the silhouette of the imaged subject object in each image into which the preliminary three-dimensional computer model is projected.

9. A method according to claim 1 , wherein the registration of the preliminary three-dimensional computer model with at least one registered set of images comprises: translating and rotating at least one of the preliminary three-dimensional computer model and the registered set of images; for different translations and rotations: projecting the preliminary three-dimensional computer model into at least one image in the set; and comparing the projection of the preliminary three-dimensional computer model with image data of the subject object in each image into which the three-dimensional computer model is projected, to calculate registration errors thereof; and determining the registration of the three-dimensional computer model with the registered set of images in dependence upon the registration errors.

10. A method according to claim 9 , wherein the silhouette of the projected preliminary three-dimensional computer model and the silhouette of the subject object are compared in each image into which the preliminary three-dimensional computer model is projected, and the registration errors are calculated in dependence upon the size of non-overlapping portions of the silhouettes.

11. A method according to claim 1 , wherein the refined three-dimensional computer model is generated by generating at least one further three-dimensional computer model of the subject object and combining each further three-dimensional computer model with the preliminary three-dimensional computer model.

12. A method of generating a three-dimensional computer model of a subject object, comprising: recording a first set of images of the subject object and a calibration pattern from different imaging positions and directions, the subject object and the calibration pattern having a first relative position and orientation for each image in the first set; changing the relative position and orientation of the subject object and calibration pattern to a second relative position and orientation; recording a second set of images comprising at least one further image of the subject object and calibration pattern, the subject object and calibration pattern having the second relative position and orientation for each image in the second set; processing image data defining the images in the first set to calculate the imaging portions and directions thereof relative to the calibration pattern in dependence upon the positions of the calibration pattern features in the images; if the second set of images comprises two or more images, processing image data defining the images in the second set to calculate the imaging positions and directions thereof relative to the calibration pattern in dependence upon the positions of the calibration pattern features in the images; processing image data defining at least some of the images in the first set and the calculated imaging positions and directions thereof to generate data defining a preliminary three-dimensional computer model of the subject object having a position and orientation relative to the images in the first set; calculating the relationship between the imaging positions and orientations of the images in the first set and the imaging positions and orientations of the images in the second set by changing the relative position and orientation of the preliminary three-dimensional computer model and the images in the second set to determine the position and orientation which substantially aligns the preliminary three-dimensional computer model with the image of the subject object in at least one image in the second set; and generating data defining a refined three-dimensional computer model of the subject object by processing data defining images from the first and second sets and the calculated relative imaging positions and orientations thereof.

13. A method of generating a three-dimensional computer model of a subject object by processing data defining a first set of images of the subject object and a calibration pattern recorded from different imaging positions and directions, the subject object and the calibration pattern having a first relative position and orientation for each image in the first set, and data defining a second set of images comprising at least one further image of the subject object and calibration pattern, the subject object and calibration pattern having a second relative position and orientation for each image in the second set, the method comprising: processing image data defining the images in the first set to calculate the imaging portions and directions thereof relative to the calibration pattern in dependence upon the positions of the calibration pattern features in the images; if the second set of images comprises two or more images, processing image data defining the images in the second set to calculate the imaging positions and directions thereof relative to the calibration pattern in dependence upon the positions of the calibration pattern features in the images; processing image data defining at least some of the images in the first set and the calculated imaging positions and directions thereof to generate data defining a preliminary three-dimensional computer model of the subject object having a position and orientation relative to the images in the first set; calculating the relationship between the imaging positions and orientations of the images in the first set and the imaging positions and orientations of the images in the second set by changing the relative position and orientation of the preliminary three-dimensional computer model and the images in the second set to a position and orientation which substantially aligns the preliminary three-dimensional computer model with the image of the subject object in at least one image in the second set; and generating data defining a refined three-dimensional computer model of the subject object by processing data defining images from the first and second sets and the calculated relative imaging positions and orientations thereof.

14. A method according to claim 1 , 12 or 13 , further comprising generating a signal conveying the refined three-dimensional computer model of the subject object.

15. A method according to claim 14 , further comprising generating a recording of the refined three-dimensional computer model of the subject object by recording the signal either directly or indirectly.

16. Apparatus operable to process image data defining images of a subject object to generate data defining a three-dimensional computer model of the subject object, comprising: an image registration calculator operable to process image data defining a plurality of images of a subject object to calculate the imaging positions and directions of at least some of the images to generate a plurality of image sets, each respective set comprising either a plurality of images having calculated imaging positions and orientations in registration or a single image; a preliminary three-dimensional computer model generator operable to generate a preliminary three-dimensional computer model of the subject object having a position and orientation in registration with the images in a first of the sets; an image-model registration calculator operable to register the imaging positions and directions of the first set of images with the imaging positions and directions of other sets of images, comprising: a three-dimensional computer model projector operable to project the preliminary three-dimensional computer model into at least one image in each of the other sets; and a position and orientation changer operable to change the relative position and orientation of the preliminary three-dimensional computer model and each respective set of images; and a refined three-dimensional computer model generator operable to generate a refined three-dimensional computer model of the subject object in dependence upon the determined registration of different image sets.

17. Apparatus according to claim 16 , wherein the image registration calculator is operable to calculate the relative imaging positions and directions of images to generate a registered set of images by calculating the imaging position and orientation of each image relative to a predetermined calibration pattern.

18. Apparatus according to claim 16 , wherein the image registration calculator is operable to calculate the relative imaging positions and directions of images to generate a registered set of images in dependence upon positions of corresponding features in the images.

19. Apparatus according to claim 16 , wherein the image registration calculator is operable to calculate the relative imaging positions and directions of images to generate a registered set of images in dependence upon features in the images identified by a user.

20. Apparatus according to claim 16 , wherein the image registration calculator is operable to process the image data to detect features in the images, and to calculate the relative imaging positions and directions of images to generate a registered set of images in dependence upon the detected features.

21. Apparatus according to claim 16 , wherein the image-model registration calculator is operable to perform iteratively the operations of projecting the preliminary three-dimensional computer model into at least one image in a registered set of images and changing the relative position and orientation of the preliminary three-dimensional computer model and the registered set of images.

22. Apparatus according to claim 16 , wherein the image-model registration calculator comprises: a three-dimensional computer model projector operable to project the preliminary three-dimensional computer model into at least one image in a registered set of images; an image data generator operable to generate image data for display showing the projection of the preliminary three-dimensional computer model relative to the subject object in each image into which the preliminary three-dimensional computer model is projected; and a position and orientation changer operable to change the relative position and orientation of the preliminary three-dimensional computer model and the registered set of images in accordance with signals input by a user; wherein the image data generator is arranged to generate updated image data for display in response to changes of the relative position and orientation of the three-dimensional computer model and the registered set of images.

23. Apparatus according to claim 22 , wherein the image data generator is operable to generate image data for display showing the silhouette of the projected three-dimensional computer model relative to the silhouette of the imaged subject object in each image into which the three-dimensional computer model is projected.

24. Apparatus according to claim 16 , wherein the image-model registration calculator comprises: a three-dimensional computer model projector operable to project the preliminary three-dimensional computer model into at least one image in a registered set of images; an alignment difference calculator operable to compare the projection of the preliminary three-dimensional computer model with the image of the subject object in each image into which the three-dimensional computer model is projected, to calculate alignment differences thereof; a position and orientation changer operable to change the relative position and orientation of the preliminary three-dimensional computer model and the registered set of images; and a registration position and orientation calculator operable to determine the registration position and orientation of the preliminary three-dimensional computer model and the registered set of images in dependence upon the calculated alignment differences.

25. Apparatus according to claim 24 , wherein the alignment difference calculator is operable to compare the silhouette of the projected preliminary three-dimensional computer model and the silhouette of the image of the subject object in each image into which the preliminary three-dimensional computer model is projected, and to calculate the alignment differences in dependence upon the areas which lie within one, but not both, of the silhouettes.

26. Apparatus according to claim 16 , wherein the refined three-dimensional computer model generator is operable to generate at least one further three-dimensional computer model of the subject object, and to combine each further three-dimensional computer model with the preliminary three-dimensional computer model to generate the refined three-dimensional computer model.

27. Apparatus operable to generate a three-dimensional computer model of a subject object by processing data defining a first set of images of the subject object and a calibration pattern recorded from different imaging positions and directions, the subject object and the calibration pattern having a first relative position and orientation for each image in the first set, and data defining a second set of images comprising at least one further image of the subject object and calibration pattern, the subject object and calibration pattern having a second relative position and orientation for each image in the second set, the apparatus comprising: an image position and direction calculator operable to process image data defining images to calculate the imaging portions and directions thereof relative to the calibration pattern in dependence upon the positions of the calibration pattern features in the images, the image position and direction calculator being operable to: process image data defining the images in the first set to calculate the imaging positions and directions thereof relative to the calibration pattern; and if the second set of images comprises two or more images, process image data defining the images in the second set to calculate the imaging positions and directions thereof relative to the calibration pattern; a preliminary three-dimensional computer model generator operable to process image data defining at least some of the images in the first set and the calculated imaging positions and directions thereof to generate data defining a preliminary three-dimensional computer model of the subject object having a position and orientation relative to the images in the first set; an image-set-relationship calculator operable to calculate the relationship between the imaging positions and orientations of the images in the first set and the imaging positions and orientations of the images in the second set by changing the relative position and orientation of the preliminary three-dimensional computer model and the images in the second set to a position and orientation which substantially aligns the preliminary three-dimensional computer model with the image of the subject object in at least one image in the second set; and a refined three-dimensional computer model generator operable to generate data defining a refined three-dimensional computer model of the subject object by processing data defining images from the first and second sets and the calculated relative imaging positions and orientations thereof.

28. Apparatus for processing image data defining images of a subject object to generate data defining a three-dimensional computer model of the subject object, comprising: image registration means for processing image data defining a plurality of images of a subject object to calculate the imaging positions and directions of at least some of the images to generate a plurality of image sets, each respective set comprising either a plurality of images having calculated imaging positions and orientations in registration or a single image; means for generating a preliminary three-dimensional computer model of the subject object having a position and orientation in registration with the images in a first of the sets; image-model registration means for registering the imaging positions and directions of the first set of images with the imaging positions and directions of other sets of images, comprising: means for projecting the preliminary three-dimensional computer model into at least one image in each of the other sets; and means for changing the relative position and orientation of the preliminary three-dimensional computer model and each respective set of images; and means for generating a refined three-dimensional computer model of the subject object in dependence upon the determined registration of different image sets.

29. Apparatus for generating a three-dimensional computer model of a subject object by processing data defining a first set of images of the subject object and a calibration pattern recorded from different imaging positions and directions, the subject object and the calibration pattern having a first relative position and orientation for each image in the first set, and data defining a second set of images comprising at least one further image of the subject object and calibration pattern, the subject object and calibration pattern having a second relative position and orientation for each image in the second set, the apparatus comprising: image position and direction calculating means for processing image data defining images to calculate the imaging portions and directions thereof relative to the calibration pattern in dependence upon the positions of the calibration pattern features in the images, the image position and direction calculating means being operable to: process image data defining the images in the first set to calculate the imaging positions and directions thereof relative to the calibration pattern; and if the second set of images comprises two or more images, process image data defining the images in the second set to calculate the imaging positions and directions thereof relative to the calibration pattern; means for processing image data defining at least some of the images in the first set and the calculated imaging positions and directions thereof to generate data defining a preliminary three-dimensional computer model of the subject object having a position and orientation relative to the images in the first set; means for calculating the relationship between the imaging positions and orientations of the images in the first set and the imaging positions and orientations of the images in the second set by changing the relative position and orientation of the preliminary three-dimensional computer model and the images in the second set to a position and orientation which substantially aligns the preliminary three-dimensional computer model with the image of the subject object in at least one image in the second set; and means for generating data defining a refined three-dimensional computer model of the subject object by processing data defining images from the first and second sets and the calculated relative imaging positions and orientations thereof.

30. A method of processing image data defining images of a subject object to generate data defining a three-dimensional computer model of the subject object, comprising: storing data defining a first set of images of the subject object recorded from different imaging positions and directions and data defining the relative imaging positions and directions; storing data defining a second set of images comprising at least one further image of the subject object; generating a preliminary three-dimensional computer model of the subject object using at least some of the images from the first set; projecting the preliminary three-dimensional computer model into at least one image in the second set; and using the projection result to generate a refined three-dimensional computer model of the subject object in dependence upon at least one image in the second set.

31. A method according to claim 30 , wherein the process of using the projection result to generate a refined three-dimensional computer model of the subject object includes adjusting the relative position and orientation of the preliminary three-dimensional computer model and the at least one image in the second set to change the projection of the three-dimensional computer model in the at least one image in the second set.

32. A method according to claim 31 , wherein the relative position and orientation of the preliminary three-dimensional computer model and the at least one image in the second set is adjusted in accordance signals input by a user.

33. A method according to claim 32 , wherein image data is generated for display to the user showing the projection of the preliminary three-dimensional computer model relative to the image subject object in the at least one image in the second set to assist the user in changing the relative position and orientation.

34. Apparatus operable to process image data defining images of a subject object to generate data defining a three-dimensional computer model of the subject object, comprising: a data receiver operable to receive data defining a first set of images of the subject object recorded from different imaging positions and directions, data defining the relative imaging positions and directions and data defining a second set of images comprising at least one further image of the subject object; a preliminary three-dimensional computer model generator operable to generate a preliminary three-dimensional computer model of the subject object using at least some of the images from the first set; a three-dimensional computer model projector operable to project the preliminary three-dimensional computer model into at least one image in the second set; and a refined three-dimensional computer model generator operable to use the projection result to generate a refined three-dimensional computer model of the subject object in dependence upon at least one image in the second set.

35. Apparatus according to claim 34 , wherein the refined three-dimensional computer model generator is operable to adjust the relative position and orientation of the preliminary three-dimensional computer model and the at least one image in the second set to change the projection of the three-dimensional computer model in the at least one image in the second set.

36. Apparatus according to claim 35 , wherein the refined three-dimensional computer model generator is operable to adjust the relative position and orientation of the preliminary three-dimensional computer model and the at least one image in the second set in accordance signals input by a user.

37. A method according to claim 36 , further comprising an image data generator operable to generate image data for display to the user showing the projection of the preliminary three-dimensional computer model relative to the image subject object in the at least one image in the second set to assist the user in changing the relative position and orientation.

38. Apparatus for processing image data defining images of a subject object to generate data defining a three-dimensional computer model of the subject object, comprising: means for receiving data defining a first set of images of the subject object recorded from different imaging positions and directions, data defining the relative imaging positions and directions and data defining a second set of images comprising at least one further image of the subject object; means for generating a preliminary three-dimensional computer model of the subject object using at least some of the images from the first set; means for projecting the preliminary three-dimensional computer model into at least one image in the second set; and means for using the projection result to generate a refined three-dimensional computer model of the subject object in dependence upon at least one image in the second set.

39. A storage medium storing instructions for causing a programmable processing apparatus to become operable to perform a method as set out in claim 1 , claim 13 or claim 30 .

40. A signal carrying instructions for causing a programmable processing apparatus to become operable to perform a method as set out in claim 1 , claim 13 or claim 30 .

41. A storage medium storing instructions for causing a programmable processing apparatus to become configured as an apparatus as set out in any one of claims 16 , 27 , 28 , 29 , 34 and 38 .

42. A signal carrying instructions for causing a programmable processing apparatus to become configured as an apparatus as set out in any one of claims 16 , 27 , 28 , 29 , 34 and 38 .